Advertisement
Published: February 22nd 2008
Edit Blog Post
Today, Monday we began our cruise through the Panama Canal. Pilot was taken on board at around 0630 in the morning and we began our approach to the canal at around 0830. Normally when a pilot is taken on board, the captain still has command of the vessel but this is the only time and place in the world where when a pilot is taken on board, the captain of the ship relinquishes full command to him.
Just a few facts about the building of the canal. The Spanish began to think of the idea back in the 16th century but due to lack of technology, it was abandoned. The next were the French in 1881 but abandoned in 1888 due to various problems. In 1903 the French sold their interest to the USA who then began to build it in 1904, completion being in 1914. The USA wanted this built for military purposes. The canal is some 50 miles in length and at the time of building cost some 380 million dollars. It operates 24hrs per day, 365 days per year and in the course of a year some 13 to 14 thousand vessels pass through it.
During
the building, the loss of lives was in excess of 25,000, mostly due to disease as the sanitation was very poor. The work force employed today for the operation is some 9000. Although built by the USA, with Panama getting their independence in the late 20th century, the canal was handed over to them in 1999. Various suggestions were made to build a second canal but due to the massive cost which would be involved, it was decided to widen it. Two widening operations have been made in the past and in fact there is a widening going on today.
So our cruise through; we had to navigate through three locks in total. The first two, Miraflors Lock and Pedro Miguel Lock, took us up a man made lake where vessels had to wait to enter the final lock. This was Gatun Lock which took us back down to the Other side.
Now like me you may say why not dig a channel from the Pacific Ocean side to the Atlantic side rather than build locks? Well, the two levels on each side are different. The Pacific Ocean is lower than the Atlantic. Strange. Perhaps Robert can find
out why and put a PS at the end of this report.
As we went through these locks, we had to be pulled attached to trains, known as Mules. One on each corner, not to pull us through but to stop us from touching the side of the locks. The ropes attaching the vessel to the Mules had to be done by two men in a boat, seems a bit out of date but it has apparently been done like this for many years and no sign of change.. These Mules cost many thousands of dollars each. The clearance between the vessel and the walls was just a few feet so the mules had to be very accurate, and indeed they were. The whole experience of the day was really enjoyed by all that had never been through the Panama before.
PS. Well, as requested, some sort of explanation as to the differing sea levels, best i could come up with, hope it helps those who wanted to know...
Extracted from www.madsci.org
As far as equalizing levels, this has occurred but introduces an idea that many people find hard to imagine. The difference
in heights is a result of a "dynamic equilibrium". Dynamic means changing, but equilibrium means balance, which we usually think of as no change. How can this be? Think of an unchanging balance as one like you can find on a scale where you place the same weight on both sides and it will balance -- always and forever. There is no new weight added or removed, no energy added or removed. This is Static equilibrium, an unchanging balance. A dynamic equilibrium involves the balance of changes. Imagine on your scale that you have cups instead of weights. Each cup the same size and is being dripped into and overflows but it will still balance if the fluid dripping in and out balances on both sides. Here there is a dynamic equilibrium with changes in mass or weight. If we want to imagine an equilibrium that also includes energy, let's have one side of the scale have a smaller cup than the other. Water drips in and overflows, but the two sides can never balance because the two cups can never hold the same amount of water. This gets a little complicated, so hang in there. The cups can't balance
each other with weight alone. The lighter cup will go up and the heavy cup will go down. You can make a dynamic equilibrium by pushing down on the lighter cup. Now you have two cups with different amounts of water that balance. Hmmm? This can only happen with the addition of energy.
there is a dynamic equilibrium. It is indeed affected by the rotation of the Earth which is where some of the energy used to maintain the balance comes from. More comes from the Sun and its heat. The energy acts through winds on the sea surface and currents which tend to cause water to "pile up" where currents are swift. Imagine the surface of your morning juice in its cup. If you swirl that juice, the surface is no longer 'level' but slanted (and the slant rotates with the swirl). This slant is maintained as long as you continue to swirl the cup. You have an equilibrium that requires energy. The moment you stop adding energy by swirling, the surface of the juice levels out. It is now a static system with a static equilibrium that is simple to understand.
There is a huge science
project (yes, scientists do science projects too) called TOPEX/Poseidon that looks at the sea surface (and other ocean information) from orbiting satellites. And there are oceanographers who specialize in studying the sea surface and what causes it to be different from flat. Some of this information is available on the Internet including really cool pictures made from satellite information. You can start looking at these locations:
Advertisement
Tot: 0.388s; Tpl: 0.01s; cc: 8; qc: 43; dbt: 0.0388s; 1; m:domysql w:travelblog (10.17.0.13); sld: 1;
; mem: 1.1mb